1. Field of the Invention
The present invention relates to a light emitting diode, and further specifically relates to a light emitting diode having a structure in which two electrodes formed on a substrate side of a semiconductor light emitting element are connected to wiring on a substrate.
2. Description of the Related Art
In recent years, light emitting diodes (LEDs hereafter), being semiconductor light emitting elements, realize high electric and optical conversion efficiency owing to an improvement of a crystal quality. With higher light emitting efficiency and smaller influence of heat generation, use of the LED in a large current is realized. Therefore, there is a wider application of the LED to a light source for illumination which requires a high luminance compared with LED for display.
In order to realize a higher output of a light emitting element, a larger-sized element is required and a resistance to a larger power is required. As an effective structure for such higher output and higher efficiency of LED, a flip chip structure using bumps is known (for example, see patent documents 1 and 2). In the flip chip structure, LED chips are used, wherein as shown in FIG. 11, a prescribed semiconductor layer 211 having a light emitting part is grown on a transparent substrate 210 by lamination, with two electrodes 212, 213 formed on the semiconductor layer 211 for current injection, and bumps 214 are formed on the electrodes 212 and 213 respectively. The LED chips with such a flip chip structure are mounted on a metal wiring 215 on the substrate 216 via the bumps 214. In the LED with the flip chip structure, the transparent substrate 210 side is used as a light extraction surface, and a light from the light emitting part is not shielded by electrodes. Therefore, high light extraction efficiency can be realized.    [Patent Document 1]    Japanese Patent Laid Open Publication No. 2008-78225    [Patent Document 2]    Japanese Patent Laid Open Publication No. 2009-59883
However, for example, in such a flip chip mounting using the bumps as disclosed in patent documents 1 and 2, a plurality of bumps need to be formed for mounting one LED, and a control of the amount and height of the bumps, a positioning work and a bonding work for mounting LED on the bumps are not easy, thus involving a problem that bonding failure easily occurs and productivity and a yield rate are hardly improved.